1. Field of the Invention
The present invention relates to the field of stretcher bar framing and canvas fastening for art canvases. More particularly this is a unique stretcher bar system using interchangeable bar segments allowing for lengthening or shortening of the sides of the frame. It features a snap fit mechanism for easy assembly or disassembly of the frame. The canvas fastener system also provides for easy mounting, re-stretching, removal, and remounting of canvas.
2. The Prior Art
In the field of art, canvas paintings are traditionally mounted to a wooden frame comprised of wooden sections referred to as stretcher bars that provide a taunt support for the stretched canvas. The stretcher bar wooden sections are assembled by means of interlocking dove-tail edges wedged together to form corner. Wooden tightening wedges are used to adjust corners to produce a perfect square. Cross braces are sometimes used as a stabilizing tension brace. Canvas or other material is stretched around and over the front perimeter of the stretcher bars and affixed to the back side by conventional means using staples or nails.
In general, current commercially known wooden stretcher bars are made in fixed sizes and frames and cannot to be customized in length and width. Several other limitations of the wooden stretcher bars include warping, difficulty in forming exact corners, and the affordability of museum depth stretcher bars. A limited number of adjustable stretcher bar frames that expand or contract in some manner are known. These adjustable frames have various limitations and are difficult to use. U.S. Pat. No. 4,519,151 discloses a hollow tubular metallic frame coupled together at the end by a co-acting pair of corner elements. The frame size can be selectively expanded and contracted by a series of five different lengths of tubular frame elements providing a means to attach fabric along the tubular edges by inserting pins in openings in the frame members. However, the disadvantage of this design is its limitation in dimension. In addition, round tubes cannot be framed and are not generally used in the field of art or accepted by galleries. U.S. Pat. No. 4,144,660 discloses an adjustable canvas stretching frame of separate, interchangeable, uniform frame segments which can be interconnected to form a limited number of size small rectangular or square frames. The primary feature of this device is to provide a means to maintain an overall rectangular shape of the frame, adjust gaps between adjacent segments of the frame, and to provide a taut surface by adjusting the tension in frame segments, with respect to each other, so a canvas can be re-stretched without damaging the canvas and/or removing the canvas from the frame. Several shortcomings to this mechanically complex design include its numerous parts and special hardware required for its assembly. Also, it does not allow for the canvas to be easily removed and reused. U.S. Pat. No. 6,675,510 discloses a lateral and longitudinal mechanized edge gripping method to avoid uneven stresses, distortion, corner wrinkles, and tearing of canvas. It primarily allows for removal and remounting of the canvas but the disadvantage is that its difficulty to evenly stretch canvas due to interference from and canvas grippers. Additional and various other prior art is also cited in U.S. Pat. No. 4,144,660, U.S. Pat. No. 4,519,151, and U.S. Pat. No. 6,675,510, and is incorporated herein by reference.
The above framing and stretching canvas references are primarily for attaching or remounting of canvas and do not allow for modifications in the overall size of the frame. The prior art does not provide the capability or means without prior training, skill, experience, or strength for quick and to easily assembly/disassembly, lengthening/shortening the stretcher bar to other frame configurations. The prior art does not allow for the stretcher bar to be easily dismantled for compact storage and for less costly transport. It also does not address the need for affordable museum quality stretcher bars.